JP4387769B2 - Winding core and transformer - Google Patents

Description

  The present invention relates to a wound iron core configured by winding a magnetic steel sheet having directionality and a transformer including the wound iron core.

  Conventionally, the structure of the wound iron core 101 in the transformer 100 is as shown in FIG. 17, in which a strip-shaped electromagnetic steel sheet 102 is wound, and this electromagnetic steel sheet 102 is wound, for example, every turn (one turn) in the width direction. Generally, after inserting the winding 103 into the cut one, the cut ends 102a of the electromagnetic steel plate 102 are butted together and closed as a joint 104, and the winding 103 is fixed. In this case, in the joint 104, it is very difficult to close the cut ends 102a of the electromagnetic steel sheet 102 once cut in close contact with each other due to the structure, and the joint 104 necessarily has a slight gap, In other words, it is a reality that voids without magnetic material are generated.

In such a wound core 101, the magnetic flux A flows in the winding direction of the electromagnetic steel sheet 102 as shown in part in FIG. 18, so that the magnetic flux A is perpendicular to the joint 104 and All of the width direction reaches at once. However, since the joint 104 is a gap and has a very high magnetic resistance as described above, the magnetic flux A tries to avoid this gap in advance, and before reaching the joint 104 as shown in FIG. It flows across a gentle inclination angle with respect to one of the electromagnetic steel sheets 102.
JP 2001-284136 A

  By the way, in recent years, instead of the electromagnetic steel sheet 102, an electromagnetic steel sheet that has been made thin and has extremely high directionality has been developed. The electromagnetic steel plate 105 (see FIG. 19) has a characteristic that magnetic flux hardly flows in directions other than the winding direction because of its high directionality. In addition, the electromagnetic steel sheet 105 has an increased presence of an insulating film between the steel sheets due to the thinning, and the magnetic flux does not easily flow in directions other than the winding direction, particularly in the thickness direction.

  As shown in FIG. 19, the magnetic flux B flowing through the electromagnetic steel plate 105 is different from the magnetic flux A flowing through the electromagnetic steel plate 102 described above, and before reaching the joint 104, the magnetic flux B flowing through either the upper or lower electromagnetic steel plate 105 may be attempted. Instead, it reaches the junction 104 having a high magnetic resistance as it is. Then, when this magnetic flux B reaches a certain point in the vicinity of the joint 104, the magnetic flux B is suddenly and at once, trying to cross the upper and lower electromagnetic steel plates 105, and the direction of instantaneous flow can be changed. On the other hand, it crosses with a substantially right angle of inclination.

  Further, since the magnetic flux B that has reached the joint 104 as described above tends to flow to the portion having the smallest magnetic resistance in the vicinity of the joint 104, the magnetic flux B is concentrated on the portion having the small magnetic resistance. Or leak into a part of the gap of the joint 104. However, the concentration of magnetic flux occurring in the vicinity of the joint 104 and the disturbance caused by leaking into the gap result in magnetic loss, and the magnetic flux B is perpendicular to the electromagnetic steel sheet 105 as described above (substantially perpendicular). When it enters the eddy current, an eddy current is generated around it, resulting in an eddy current loss.

  Recently, an electrical steel sheet called a magnetic domain control electrical steel sheet having a marking (scratch) formed on the surface has been commercialized. If this magnetic domain control electrical steel sheet is used for the electrical steel sheet 105, the generation of eddy currents can be suppressed, but an effective countermeasure can be taken for magnetic loss due to the concentration and disturbance of the magnetic flux B in the vicinity of the joint 104. In fact, this has led to deterioration of the characteristics of the transformer 100 as it is. In other words, even if the wound iron core 101 is configured using a magnetic steel sheet having a high directionality, such as a magnetic domain control magnetic steel sheet, the advantage of the characteristic having the high directionality is sometimes the magnetic flux B as described above. In some cases, this causes a demerit that causes concentration or disturbance of the user.

  The present invention has been made in view of the above circumstances, and its purpose is to provide a wound iron core and a transformer that can fully utilize the characteristics as a merit even when a magnetic steel sheet having high orientation is used. Is to provide.

In order to achieve the above object, the wound iron core of the present invention is composed of a plurality of unit iron cores, each of which is formed by cutting a wound belt-shaped electromagnetic steel sheet into one or more turns to make a unit iron core. in wound core was Unishi I shall be the butt joint of the cut ends of the core, the cut end of the unit iron core, that is characterized by being configured so as to be inclined with respectively different angles to the winding direction It is characterized (Invention of Claim 1).

  According to this configuration, the magnetic flux flowing through the unit iron core made of the electromagnetic steel sheet does not reach all at once in the width direction of the unit core at the joint, but sequentially reaches in the width direction. Therefore, magnetic flux concentration does not occur in the vicinity of the junction. Furthermore, by inclining each cut end of the unit core, the magnetic flux does not easily flow in the width direction at the joint, so that the magnetic flux that has reached the joint immediately flows to the upper and lower electromagnetic steel sheets, Even if the magnetic flux flows through a unit iron core composed of a magnetic steel sheet having a high directivity, for example, a magnetic domain control electrical steel sheet, it smoothly flows over either the upper or lower magnetic domain control electrical steel sheet and flows through the gap in the joint. Disturbances due to things can also be prevented.

The wound core of the present invention, the cutting edge of the unit of the iron core, which is configured so as to be inclined with respectively different angles to the winding direction, for example in small transformers, etc., the convenience and the dimensions of the structural requirements Even if the yoke part cannot be removed for a long time, etc., it is possible to reliably secure a lap part between adjacent electromagnetic steel sheets, that is, between unit iron cores.

In addition, it is composed of a plurality of unit cores that are made by cutting the wound strip-shaped electrical steel sheet into one or more turns to make a unit core, and butt the cut ends of each unit core to form a joint, In the wound core in which each joint is shifted in the winding direction, the cut end of the unit core is configured to be inclined at an angle of 50 ° to 75 ° in the winding direction, and each unit core is formed of the joint. You may comprise so that it may be pressed from the both sides of the width direction by a press member in the vicinity, and may shift | deviate to the said width direction (invention of Claim 3 ).
According to this configuration, even if a gap exists in the joint, the gap is closed when the electromagnetic steel sheet, that is, the unit core is displaced in the width direction, so that the cut ends of the electromagnetic steel sheet can come into contact with each other.

  As is clear from the above description, according to the wound core and transformer of the present invention, even when using a magnetic steel sheet having high directivity, a so-called magnetic domain control electromagnetic steel sheet, the characteristics are fully utilized as a merit. It is possible to obtain an excellent effect of being able to

<First embodiment>
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 shows a schematic external view of a single-phase transformer 1. The wound iron core 2 is a plurality of unit iron cores that are made of a thin and highly oriented magnetic steel sheet, for example, a magnetic domain control electromagnetic steel sheet, and the wound product is cut every turn (one turn) to form a unit core. 2a. Then, the winding 3 is fitted into the wound core 2 with the cut ends 4 of the unit cores 2a being expanded. Thereafter, the cut ends 4 of the unit iron cores 2a are butted together and closed as a joint portion 5, whereby the transformer 1 is configured. Therefore, in the wound core 2, the joint portion 5 is formed at the upper yoke portion.

  As shown in FIG. 2, the unit core 2a is cut so as to be inclined at a cutting angle θ (for example, θ = 60 °) with respect to the winding direction. 4 has a small gap, that is, a so-called high magnetic resistance gap. Moreover, each unit iron core 2a is comprised so that each may have the parallelogram-shaped wrap part 6 as shown in FIG. 2 based on shifting | deviating for every sheet in the winding direction in the vicinity of the junction part 5. FIG. ing. Then, due to this, the joint portion 5 is shifted stepwise in the winding direction, and when these joint portions 5 are viewed from the width direction, as shown in FIG. It is configured as if it were a step lap joint.

  Here, FIG. 4 shows magnetic flux density (T) on the horizontal axis and BF on the vertical axis (BF in this case) with the cutting angle θ of the cut end 4 in the joint 5 when the excitation frequency is 50 (Hz) as parameters. Is a graph of experimental data showing the ratio of the wound core loss to the material loss = material loss / wound core loss). As is apparent from FIG. 4, when the cutting angle θ = 60 ° (also shown in FIG. 2), the BF shows a good overall low value for all magnetic flux densities. Then, even when θ = 50 ° and θ = 75 ° with θ = 60 ° as a boundary, BF shows a relatively good low value for all magnetic flux densities. However, at θ = 45 ° and θ = 90 ° (right angle), BF becomes a slightly high value.

  The reason for this is that by setting the cutting angle θ of the cutting end 4 of the joint portion 5 to be in the range of 50 ° to 75 °, the magnetic flux gradually moves from the order of reaching the joint portion 5 to either the upper or lower unit core 2a. Since it can flow, it becomes difficult for magnetic flux concentration and rapid increase of magnetic flux density due to this to occur, and by setting the cutting angle to the above range, the cutting end 4, that is, in the vicinity of the junction 5 or immediately before This is because the magnetic flux escaping in the width direction is reduced, and the effect of more magnetic flux flowing over the upper and lower unit cores 2a is enhanced. In addition, when the junction part 5 becomes a right angle (90 degrees) with respect to the flow of magnetic flux, this corresponds to a prior art.

  As described above, according to the first embodiment, the cutting angle θ of the cutting end 4 of the joint portion 5 is set to θ = 60 °, so that the magnetic flux is gradually moved up or down from the order of reaching the joint portion 5 sequentially. The unit core 2a can flow over the unit core 2a. Further, the unit core 2a has a wrap portion 6 in the vicinity of the joint portion 5, and the magnetic flux can be moved up and down by avoiding the joint portion 5 having a high magnetic resistance in advance. Since it is easy to cross over the unit iron core 2a, the magnetic flux density is rapidly increased by the concentration of the magnetic flux due to the magnetic flux flowing at the joint 5, the magnetic flux is disturbed, and the inclination angle of the magnetic flux with respect to the unit iron core 2a due to these. It is possible to suppress the generation of eddy currents due to the right angle of each, and by extension, the magnetic domain control electrical steel sheet, that is, the excellent characteristics that make full use of the merits of a highly oriented electrical steel sheet Transformer 1 Rukoto can.

<Second embodiment>
A second embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and only different parts will be described.
In the second embodiment, the joint portion 10 formed in each unit core 2a is configured to intersect in the stacking direction of the unit core 2a. These joint portions 10 are cut at an angle of θ = 60 °, and the unit cores 2a are laminated while being inverted one by one, so that the cut angles of the cut ends 4 in the adjacent joint portions 10 are 180 with respect to each other. The respective joints 10 are made to cross each other in the stacking direction of the unit cores 2a. At this time, a diamond-shaped hole 10 a is formed at the intersection center of each joint 10. In addition, the cutting angle of the cutting end 4 in the junction part 10 should just exist in the range of 50 degrees-75 degrees, as shown in FIG.

Each of the unit cores 2a has a triangular wrap portion 11 based on the intersection of the joint portions 10, and due to this, the joint portions 10 are also shifted in a staggered manner in the winding direction. When these joint portions 10 are viewed from the width direction, they are configured as if they are general alternating lap joints as shown in FIG.
Since the joint 10 in the unit core 2a has a high magnetic resistance, as described above, the magnetic flux avoids the joint 10 and tries to cross from the low magnetic resistance to the upper or lower unit core 2. If the lap portion in the unit core 2a is small or not, the flow of magnetic flux concentrates at a low magnetic resistance in the vicinity of the joint 10 and becomes a high magnetic loss due to disturbance, resulting in a transformer (for example, in FIG. Degrading the characteristics of the transformer 1) shown.

  However, according to the second embodiment, the adjacent unit cores 2a have the triangular wrap portions 11, and the lap portions 11 are configured such that the adjacent joint portions intersect each other. Since the wrap portion 11 has a relatively large area in the vicinity of the magnetic flux 10, the magnetic flux easily avoids the joint 10 in advance by the lap portion 11, and the magnetic loss is less likely to occur due to the magnetic flux concentration and disturbance. The characteristics of the transformer (1) can be improved. Furthermore, since each cutting end is inclined at an angle of 60 °, the magnetic flux reaching the joint 10 can be smoothly moved up and down without causing further rapid increase or disturbance of the magnetic flux density due to the concentration of the magnetic flux. It can flow over the unit core 2a, and the above effect can be further improved. In this case, the effects of the first embodiment described above can be obtained in the same manner.

<Third embodiment>
In FIG. 6 showing the third embodiment of the present invention, for example, a bolt 20 is inserted as a fastener into the diamond-shaped hole 10a formed at the center of intersection in the joint 10 of the second embodiment. The unit core 2a is configured to be tightened with a nut 21 in the stacking direction. In this case, a holding plate 22 is disposed on each of the upper and lower unit cores 2a.

The transformer (1) is sometimes subjected to artificial vibration during loading or transportation, or unavoidable excitation vibration. However, according to the third embodiment, since the unit core 2a is fastened and fixed in the stacking direction, it is not unraveled and the overall strength of the transformer (1) can be improved. In addition, since the iron core binding or the like is not necessary, the cost is improved.
In the third embodiment, the bolt 20 and the nut 21 are used as the fasteners. However, the present invention is not limited to this. For example, a billet or the like may be used.

<Fourth embodiment>
In FIG. 7 showing the fourth embodiment of the present invention, a suspension bar 20a integrally provided at one end of the bolt 20 in the third embodiment is fixed to a part of a transformer component (not shown). The entire yoke portion 30 is configured in a suspended state. In this case, a resin clamp 31 is press-fitted into the upper and lower spaces between the wound iron core 2 and the winding 3 so that the wound iron core 2 is not deformed. They are connected by a connecting rod 32.

Including magnetic domain control magnetic steel sheet, become relative to the winding direction of the common magnetic steel sheets (length direction), the compressive stress to the legs 33 especially is applied, hardly flux in this portion to flow, which is a magnetic Due to the loss, the characteristics of the transformer (1) deteriorate. However, according to the fourth embodiment, the weight of the wound core 2 and the load of the winding 3 are supported by the transformer component so that no compressive stress is applied to the legs 33. Therefore, the deterioration of the characteristics of the transformer (1) can be prevented with a relatively simple structure.

<Fifth embodiment>
A fifth embodiment of the present invention will be described with reference to FIG. The same parts as those in the first to fourth embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.
In the fifth embodiment, the joints 40 formed by the unit cores 2a are inclined at different angles in the winding direction of the unit cores 2a, in other words, each joint 40 is at one end in the width direction. It is formed so as to be radial with the reference point 41 located at the center. That is, each joint 40 (the cut end 4 thereof) is cut so that the cutting angle sequentially increases every 10 ° in the range of θ = 30 ° to 90 ° with respect to the winding direction. In this case, a lap portion 42 having a triangular shape and a different area is formed at the joint portion 40 of the adjacent unit cores 2a, and each lap portion 42 gradually increases as the distance from the vicinity of the reference point 41 increases. is there. The reference point 41 is a gap in the stacking direction.

  For example, in a small transformer or the like, there is a case where the yoke portion cannot be removed for a long time due to structural reasons, dimensional requirements, and the like. In this case, for example, when the joints 5 and 10 are formed by the step lap joint as shown in FIG. 2 or the alternating lap joint as shown in FIG. Because the part is short, a part of the wrap part 6 or 11 (part at the end part of the wrap part 6, 11) extends to the curved part of the wound core 2, so-called corner part. Since the wrap portions 6 and 11 are partially curved, the normal wrap portions 6 and 11 cannot be formed, or even if possible, a very small situation may occur. However, if the wrap portions 6 and 11 cannot be formed or are very small, the magnetic flux reaching the joint portions 5 and 10 cannot be passed over the upper or lower unit core 2a or cannot be crossed, so the flow of magnetic flux is disturbed, This results in high magnetic loss, leading to deterioration of the characteristics of the transformer (1).

However, according to the fifth embodiment, even when the yoke part such as a small transformer cannot be taken long, the unit cores 2a having the joints 40 having different cutting angles are stacked to be adjacent to each other. The lap portions 42 having different triangular areas between the upper and lower unit cores 2a can be reliably and normally secured, and the magnetic flux reaching the joint portion 40 is Since it can flow over one of the unit cores 2a, even a small transformer does not deteriorate its characteristics.
In the fifth embodiment, the number of unit cores 2a is seven, but the number of unit cores 2a is not particularly limited.

<Sixth embodiment>
In the sixth embodiment of the present invention in which the wound iron core 2 in the fifth embodiment is configured as one block 43 and two blocks 43 are stacked, first, as shown in FIG. Each reference point 41, 41 is set to a position where both ends opposed to each other in the width direction are shifted, and based on this, each joint 40, 40 formed so as to be radially centered on these two reference points 41, 41 is provided. The respective blocks 43 and 43 are configured to be at positions where they are shifted by 180 ° and intersect each other.

Further, in the modification shown in FIG. 10, the two reference points 41 and 41 are separated from each other at the same end in the width direction, and based on this, the reference points 41 and 41 are formed to be radial. Furthermore, each joint part 40 and 40 is comprised so that it may become the position which inverts every each block 43 and 43 and mutually cross | intersects.
For example, in a small transformer or the like, when a wider wrap portion is required, the block 43 is configured by stacking a plurality of stages, for example, two stages, so that the wrap portion is widened. However, as described above, the block 43 has the reference point 41 at one end in the width direction, and the reference point 41 is a gap in the stacking direction. Therefore, when the blocks 43 are stacked to form the wound core 2, the lap portions 42 in the unit core 2a in the vicinity of the reference point 41 are small, so the reference point 41 is concentrated on one end in the width direction. As a result, the small lap portions 42 are concentrated in this portion. In such a case, particularly in a small transformer having a high design magnetic flux density, the leakage magnetic flux is increased at the position where the reference points 41 are aligned, in other words, the small wrap portions 42 are concentrated. For example, an eddy current is generated in the clamp 31 or the like as shown in FIG. 7, and a local temperature rise or thermal bending occurs in this portion.

  However, according to the sixth embodiment, for example, in the transformer (1) of FIG. 9, the reference point 41 is shifted from both ends facing each other in the width direction, and the reference point 41 is one end in the width direction. Therefore, the eddy current generation site due to the leakage magnetic flux can be separated, and a local temperature rise or the like with respect to the clamp 31 or the like caused by this can be pushed. Furthermore, the lap portion 42 between the adjacent upper and lower unit iron cores 2a can be reliably secured, and the positions and distances of the joint portions 40 are formed sparsely, and the cutting angles of the cutting ends 4 are also mutually different. Since they are different, the junction 40 can improve the characteristics of the transformer (1) without causing an increase in magnetic flux density or disturbance due to the concentration of magnetic flux.

Further, in the transformer (1) of FIG. 10, since the reference point 41 is located at a position away from the same end in the width direction, the same effect as the transformer (1) of FIG. 9 can be obtained.
In the fifth and sixth embodiments, the cutting angle of the cutting end 4 in each of the joint portions 40 is in the range of 30 ° to 90 °, and the cutting angle interval is different every 10 °. However, the present invention is not limited to this, and the cutting angle, the cutting angle range, and the cutting angle interval can be appropriately changed depending on the number of stacked unit cores 2a, etc. It is good also as a structure which shifts every 40.

<Seventh embodiment>
A seventh embodiment of the present invention will be described with reference to FIGS. The same parts as those in the first to sixth embodiments are denoted by the same reference numerals, detailed description thereof will be omitted, and only different parts will be described.
In the seventh embodiment, the cut ends 4 of the unit iron core 2a are initially set to have a width such as a left cut end 50 indicated by a one-dot chain line and a right cut end 51 indicated by a two-dot chain line in FIG. It is in a state that is flush with the direction. That is, it is the state of FIG. 2A in the first embodiment. Then, in this state, the left cut end 50 and the right cut end 51 are pressed from opposite directions at positions shifted in the width direction by, for example, leaf springs of an elastic body as pressing members. ), The cut ends 50 and 51 are displaced in the width direction, and the cut ends 50 and 51 are in contact with each other. This is because the left cut end 50 is shifted downward in FIG. 11A and the right cut end 51 is shifted upward in FIG. 11 due to the pressing.

  Closely contacting the joint 5 of the unit core 2a greatly reduces the magnetic resistance of the joint 5 and is therefore very effective in improving the characteristics of the transformer (1). It is extremely difficult in terms of top and material. However, due to the requirement of the dimensions of the transformer (1), if the width of the joint 5 is too large, not only the required dimensions can be met, but also the transformer ( The characteristic of 1) itself is greatly deteriorated.

  However, according to the seventh embodiment, both the cut ends 50 and 51 are pressed from the positions shifted in the width direction in the joint portion 5, and the cut ends 50 and 51 come into contact with each other so that the joint portion 5 is Since the magnetic resistance at the junction 5 is greatly reduced, the characteristics of the transformer (1) can be improved. FIG. 12 is a graph of experimental data showing the magnetic flux density (T) on the horizontal axis and the iron loss (W / kg) at 50 (Hz) on the vertical axis. As is apparent from FIG. 12, the above effect is gradually effective particularly when the magnetic flux density exceeds 1.30, and becomes good in proportion to the magnetic flux density.

In addition, even when the width of the joint portion 5 becomes larger than expected for some reason during manufacturing, the width can be reduced by pressing both the cut ends 50 and 51 from both width directions. Therefore, for example, a dimensional error can be corrected.
In the seventh embodiment, the leaf spring is used as the pressing member. However, the present invention is not limited to this. For example, a wave spring, a coil spring, or a resin such as rubber may be used.

<Eighth embodiment>
In the eighth embodiment of the present invention, the cut ends of the unit cores 2a are first mutually arranged like a left cut end 60 indicated by a one-dot chain line and a right cut end 61 indicated by a two-dot chain line in FIG. In this state, the left cutting edge 60 is cut at an angle of 10% with respect to the right cutting edge 61 while being flush with the width direction. Then, in this state, the left cut end 60 and the right cut end 61 are pressed from positions shifted in the both width directions, so that the cut ends 60 and 61 of each other are shown as indicated by the solid line in FIG. Is shifted in the width direction, and the cut ends 60 and 61 are in contact with each other.

  To reduce the width of the joint, pressing from both width directions is an effective means. For example, when the radius of curvature of displacement due to pressing is small and the cutting edges are parallel, contact between the cutting edges Can be point contact. When the cut ends are in point contact with each other in this way, a large gap partially remains at the junction, and eventually the magnetic resistance at the junction cannot be reduced, and the characteristics of the transformer are not improved.

However, according to the eighth embodiment, the right cut end (the other cut end) 61 is inclined by 10% with respect to the left cut end (the one cut end) 60, and the left side is pressed by pressing from both width directions. Since the end of the cutting end 60 quickly contacts the right cutting end 61 and further pressing further, the left cutting end 60 can surely come into surface contact with the right cutting end 61, so that the gap of the joint 62 is more reliably secured. As a result, the magnetic resistance of the junction 62 can be reduced, and the characteristics of the transformer (1) can be improved reliably. Here, the ratio of the angle at which the other cut end is inclined with respect to the one cut end is preferably within 10%, and if it exceeds this, the unit core 2a may be largely distorted during pressing.
In the eighth embodiment, the left cut end 60 is inclined at 10% with respect to the right cut end 61. However, the present invention is not limited to this, and the right cut end 61 is not limited thereto. The left cutting end 60 may be inclined and cut, or both cutting ends 60 and 61 may be inclined relative to each other by 10%.

<Ninth embodiment>
A ninth embodiment of the present invention will be described with reference to FIG. The same parts as those in the seventh embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and only different parts will be described.
In the ninth embodiment, as shown in FIG. 1 4, the seventh cutting edge 50, 51 becomes space offset in the width direction as described in the examples above, the resin containing the magnetic material 70 Is applied. Here, as the magnetic material, for example, iron powder is used, and as the resin, for example, an epoxy resin is used. This resin 70 is a space, that is, the cut ends 50 and 51 in which voids are generated. It is applied so as to be flush with the side surface of the unit core 2a.

The magnetic flux that has reached the cut ends 50 and 51 where gaps have occurred in the width direction cannot flow any more, and the flow direction changes suddenly and flows into the neighboring unit core 2a. As a result, the magnetic flux density suddenly rises and is disturbed, and the characteristics of the transformer (1) deteriorate.
However, according to the ninth embodiment, the resin 70 containing the magnetic material is applied to the cut ends 50 and 51 where the gaps are generated, and the magnetic flux reaching the cut ends 50 and 51 is the resin 70. Therefore, the characteristics of the transformer (1) are improved without causing a rapid increase or disturbance of the magnetic flux density due to the concentration of the magnetic flux. Further, as the time elapses, the resin 70 is cured and the unit cores 2a and the cut ends 50 and 51 are fixed to each other, so that the core binding is not required and the cost is improved. Since vibration, magnetic noise, etc. are absorbed, a higher quality transformer (1) can be obtained. Furthermore, the hollow cut ends 50 and 51 are sharp, but by applying the resin 70 to be flush with the side surface of the unit core 2a, the cut ends 50 and 51 are caught or damaged by other members. Can be prevented.
The configuration of the ninth embodiment may be applied to the eighth embodiment.

<Tenth embodiment>
In the tenth embodiment of the present invention, as shown in FIG. 15, the resin 70 similar to that in the ninth embodiment is densely filled in the gap of the joint portion 5 as described in the first embodiment. Has been.
As described above, since the joint portion 5 having a gap has a very high magnetic resistance, the magnetic flux tends to flow over the upper and lower unit cores 2a in order to avoid this. As a result, an increase in magnetic flux density or disturbance due to the concentration of magnetic flux occurs in the vicinity of the junction 5, and the characteristics of the transformer (1) deteriorate.

However, according to the tenth embodiment, the bonding portion 5 is densely filled with the resin 70 containing the magnetic material, and the magnetic flux can flow through the resin 70. The resistance is reduced, the characteristics of the transformer (1) are improved, and the same effect as in the ninth embodiment can be obtained.
It should be noted that the resin 70 in the ninth and tenth embodiments can be applied to or filled in various shapes of cut ends and joints, and within a range not departing from the gist, It can be changed as appropriate.

  Further, in the resin 70, the content of the magnetic material contained in the resin 70 is desirably around 70% by mass. If the magnetic material is separated from the resin 70, problems arise in the fluidity and adhesion of the resin 70. In addition, the magnetic material is not limited to iron powder. For example, phylite powder and the like can not flow magnetic flux as much as the iron powder, but the insulation is good, and the resin flows into the winding insulation (coil insulation) etc. However, it is difficult to cause insulation failure.

<Eleventh embodiment>
An eleventh embodiment of the present invention will be described with reference to FIG. The same parts as those in the fifth embodiment are denoted by the same reference numerals, detailed description thereof will be omitted, and only different parts will be described.
In the eleventh embodiment, each unit core 2a is configured so that the cutting angle of the cutting end 4 in the joint section 40 of the fifth embodiment is different in the stacking direction, and the concave portion 80 and the convex portion 81 as positioning portions are provided. Is formed by caulking in one place. The concave portion 80 and the convex portion 81 have a substantially truncated cone shape, and are formed in the vicinity of one end portion in the width direction of the unit core 2a. The convex portions 81 of the unit cores 2a engage with the concave portions 80 of the adjacent unit cores 2a, and based on this, the relative positions of the unit cores 2a are not shifted.

When laminating a plurality of unit cores 2a, the unit cores 2a are laminated after being cut every turn. In this case, the unit cores 2a are displaced in the width direction or dispersed due to vibration or the like. Then, it is very difficult to accurately stack these unit iron cores 2a again correctly, or to accurately abut each of these cut ends 4 again.
However, according to the eleventh embodiment, since the unit cores 2a can be engaged with each other by the concave portions 80 and the convex portions 81 formed respectively, the unit cores 2a are displaced or scattered. Therefore, workability is improved when the wound core 2 is formed.

In the eleventh embodiment, the positioning portion is the concave portion 80. However, the positioning portion is not limited to this. For example, the shape may be a groove shape or a convex portion.
The configuration of the eleventh embodiment may be applied to the first to fourth and sixth to tenth embodiments.
In the first to eleventh embodiments, it is particularly preferable to use a magnetic domain control electrical steel sheet having a magnetic flux alignment factor of 150 or more at a magnetic flux density of 1.5T.

Moreover, in the said 1st thru | or 11th Example, although the wound material of the electromagnetic steel plate was cut | disconnected for every turn (one turn) and the unit iron core 2a was comprised, it cut | disconnects for every multiple turns, for example, unit An iron core may be configured, and in this case, every two or three turns is desirable for every multiple turns.
Similarly, in the first to eleventh embodiments, a single-phase transformer is applied. However, the present invention is not limited to this. For example, a three-phase transformer used for an embossed iron core or a five-leg iron core. You may apply to.

The perspective view of a transformer which shows the 1st example of the present invention. (A) is a partial enlarged view of a yoke part, (b) is the perspective view. Expanded side view of the yoke part Diagram showing the relationship between magnetic flux density and BF (= material loss / winding core loss) FIG. 2 shows a second embodiment of the present invention and is equivalent to FIG. The expanded sectional view of a yoke part which shows the 3rd example of the present invention. 4 shows a fourth embodiment of the present invention and is equivalent to FIG. FIG. 9 shows a fifth embodiment of the present invention and is equivalent to FIG. FIG. 8 shows a sixth embodiment of the present invention and is equivalent to FIG. FIG. 9 equivalent diagram showing a modification FIG. 9 shows a seventh embodiment of the present invention and is equivalent to FIG. The figure which shows the relationship between the magnetic flux density and the iron loss before pressing and after pressing 8 shows an eighth embodiment of the present invention, and is equivalent to FIG. FIG. 11 shows the ninth embodiment of the present invention and is equivalent to FIG. The 10th Example of this invention is shown, FIG.2 (b) equivalent figure FIG. 11 shows an eleventh embodiment of the present invention, where (a) is a view corresponding to FIG. 1 equivalent diagram showing a conventional example Action diagram 18 equivalent diagram

Explanation of symbols

In the drawings, 1 is a transformer, 2 is a wound core, 2a is a unit core, 4 is a cut end, 5 is a joint, 10 is a joint, 10a is a hole, 20 is a bolt (clamp), 21 is a nut ( Fasteners), 40 is a joint, 43 is a block, 70 is resin, 50 is a left cut end (cut end), 51 is a right cut end (cut end), 60 is a left cut end (cut end), and 61 is right cut end (cut end), 80 is a concave portion (positioning portion).

Claims (9)

Constructed a strip of an electromagnetic steel sheet which is wound in a plurality of unit cores to single turn or multi-turn unit cores and cut into times, was Unishi I shall be the joint butt the cut end of each of the unit cores In the wound iron core,
The wound core is characterized in that the cut ends of the unit core are configured to be inclined at different angles in the winding direction. A wound core comprising: a plurality of blocks, each having the wound core according to claim 1 as a block, and a joining portion of adjacent blocks intersecting each other. It is composed of a plurality of unit cores that are made by cutting a wound strip-shaped electrical steel sheet into one or more turns to make a unit core. In the wound iron core that has been shifted in the winding direction ,
The cutting end of the unit core is configured to be inclined at an angle of 50 ° to 75 ° in the winding direction,
Each of the cores is pressed from both sides in the width direction by a pressing member in the vicinity of the joint and is displaced in the width direction . In the wound iron core according to claim 3,
A wound core characterized in that the other core is displaced by 10% relative to the cutting angle of one cutting end of each unit core. In the wound iron core according to claim 3 or 4 ,
A wound iron core, wherein the pressing member is made of an elastic body . In the wound iron core according to claim 3 or 4 ,
A wound iron core in which a resin containing a magnetic material is applied to a side surface where the electromagnetic steel sheet is displaced . In the wound iron core according to any one of claims 1 to 6 ,
A wound iron core characterized in that the joint is filled with a resin containing a magnetic substance . In the wound iron core according to any one of claims 1 to 7 ,
Each unit core is formed with a positioning portion that engages with each other . A transformer comprising the wound core according to any one of claims 1 to 8 .

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